Sid Caesar, a television pioneer who reigned as the king of live TV sketch comedy in the 1950s with his inspired brand of mimicry, pantomime and satire on the classic comedy-variety series “Your Show of Shows” and “Caesar’s Hour,” died Wednesday. He was 91.

Caesar died at his home in Beverly Hills after a brief illness, according to his biographer and friend Eddy Friedfeld.

A two-time Emmy Award-winning performer during his TV heyday in the `50s, Caesar has been hailed as “one of the great TV clowns,” “one of television’s most inventive performers” and “a genius at making people laugh.”

“Television had its share of comedy geniuses,” Times television critic Howard Rosenberg wrote in 1994. “Yet arguably none has been as uniquely gifted and inventive as Caesar. Watching him perform, you just know light bulbs are popping continuously in his brain.”

With his flair for verbal and physical comedy honed while performing during his World War II service in the Coast Guard and in nightclubs and theaters after the war, Caesar burst on the national scene in 1949 as the star of the “Admiral Broadway Revue,” a live, hourlong show from New York that aired Friday nights simultaneously on NBC and the DuMont network.

The Max Liebman-produced show, which was built around Caesar and teamed him with comedic actress Imogene Coca for the first time, featured guest stars, comedy sketches and large production numbers.

The “Admiral Broadway Revue” was a hit — so much so that it was canceled after less than five months when the Admiral Corp. withdrew its sole sponsorship: It reportedly needed to use the money it had been putting into the program to build a new factory to keep up with the skyrocketing number of orders for its TV sets generated by the show.

But the “Admiral Broadway Revue” was only a warmup for what Caesar later called the main event: “Your Show of Shows.”

The live, 90-minute Saturday night show, produced by Liebman and showcasing the comic ensemble of Caesar, Coca, Carl Reiner and Howard Morris, aired from 1950 to 1954 and won two Emmys for best variety show.

Caesar later likened performing the 90-minute show live before a theater audience, without the aid of cue cards or TelePrompTers, to doing a new Broadway show each week. And they did it 39 weeks each season.

Out of that pressure cooker came innumerable classic comedy moments.

There were domestic sketches, including one in which Caesar and Coca are a married couple trying to decide how to tip at a fancy restaurant. In another, Caesar is a husband who is so anxious about a big meeting the next morning that he can’t fall asleep. But instead of taking sleeping pills, he mistakenly takes pep pills.

In one of the show’s most memorable sketches, Caesar, Coca, Reiner and Morris wordlessly played the figures on a large town clock in Bavaria that appear with mechanical precision on the hour, until the clock goes on the fritz.

Caesar later said the key to the show’s success “unquestionably was the writing.”

Among the members of the “Your Show of Shows” legendary writers’ room, in addition to Brooks, were Mel Tolkin, Lucille Kallen, Tony Webster, Joe Stein, Neil and Danny Simon, and Reiner (a self-described “writer without portfolio”).